Spring testing machine



g- 8, 3- c. A. THELANDER 1,921,793

SPRING TESTING MACHINE Filed March 1, 1928 17 51 20 j I /ZZ Ea. f Z6 J7M fi U I; J a 6 0 Zf 1f 1" //f zu 3 L 30 6 32 59 i 19 13 a 53 E '15duced simplyto the matter of inserting springs, screw by means ofsuitable'gearingwhereby JTU set standard or is too weaker-too strong,indicator hand 15. A plunger 16 is received in 5 I 50 may be varied tosuit requirements.

Patented Aug QjS 1 933: ay; g

UN E STATES vP TEIWYQF t t v I: lanner l SPRING TESTING MACHINE Carl A.Thelander, Rockford, Ill. assignor, by

mesne assignments, to Borg-Warner Corpora- -tion, Chicago, Ill., aCorporation of Illinois Applicationdv larch 1,192 Serial 'nc'gzsslzss 2Claims. (Ci ia-E51) This invention relates to a power operated,connection between the power operated crank hand-fed spring testingmachine. and the 'D t fl and I In the testing of springs, such asc'oiled com- Fig. v3 .is a section taken on .the line 3-3 of pressionsprings, it has been customaryto per- Fig. 2.:

5 form the operation entirely by hand, usingalever The samereferencenumeralsare applied tocor- 60 pulled down by hand to compresseach spring to responding parts throughout the views. a the desiredamount on the platform of a, scale, The machine comprises abase4shavingva hol-j the handof which designates the amount of low column 5rising therefrom. The head end6 pressure in poundsor other suitableunits. The 'ofthe latterfoverhangs a table"? carried by'a' 10 principalobject of the present invention is to probracket 8 adjustably mounted onthe post 9, the f f 1 vide a power operated machine for performingadjustment means suitably comprisinga screw the operation referred.toWhereby one operator 10 operating in a nut .11 carried by the bracketcan readily do the work of two or even more 8 and the screw beingoperable by hand or by without showing fatigue, the operation beingrepower. [A hand crank 10a is conn'ected with the one after another,beneath a presser foot on a operationof the crank 10a will causerotation. continuously reciprocated plunger and simultaof the screwmheta -"T formslai rigidSUP-r neously noting the scale reading to determineport for a scale 12 which may be of anysuitable or Whether a springconforms to a predetermined preferred type. having aplatform 13, dial lgand Inthe machine of my invention" I provide in bearings 17 provided onthe head 6 and'is a connection with a scale platiorm a CQlltlLilOllSl'yranged to reciprocate vertically above the plat reciprocated plungeroperating vertically above form 13 at a rate determined by the speed ofthe H the platform, the plunger having a pifesser foot i' electric motor18 and reduction gearing 19. proi fixed adjustablyonthe lowerendjthereo'f vand arlvided for the operation of the'machine by power. sorangedtobeset toleave a predetermined r'equired Any suitable means maybe employed providing clearance between it. and the latform; at the ac nn between h p n 6 n h lower end of its stroke to theend that one mayauction s a n In the present embodiment determine the load a spring willbe under when* I have shown a rocker'beam 20 pivoted in the compressedto a certain prescribed length,-the' head 6ra5 at having slidingpivotitl00117111604 W loading of thespring being indicated :by'the retdt 22 witha collar 23 fixed n r u s' 'ing'on the dial of the scale.v Iprefr tooperate 16 betweenthe bearings.17.....'Il1e other end of the i thcplunger "in. su ha a .thg,t th s m ill rocker beam 20 has pivotalconnection at 24- have a sufficient {pause ;at the lower end of itswitha pltman rod 25 connected by a crank pin v r stroke to allow theindicator hand of the sca 26 with a'crankelement 2'7 driven by theterminak I enough time to cease vibrating so that areadingij ear of thereduction. g ns 1 twil be evi can be made. without eyestrain, the meansemdent from, e t nifi hu x vanc d V ployed in the present embodimentbeing a rocker hat i th per i n f the m0tj011'l8 he pl n beam operatedby a pitman rod connected with l is c n in ly ip oc t w rd an aw y acrank elementythe crank atdead center caus i th f F 9a rate detlemined,a ingthe plunger t e t t enough to avoid stated before, by the speed ofthe motor and the the excessive vibrationiof the indicator hand. I driveratioiafiorded by'the reduction sea n .1

'also prefer to provide means for adjusting the re- In the i g of ercompressionspringsi lationship between the plunger andthe scale plat.-for x it E deslrgd to k What presswf'e fe form to take diflerent lengthsof springs where Spnng develops when compressed to m the adjustment isnot within the limits afforded li g gg g f g lowefgend i by theadjustable presser foot, and also provide p g a 6 8 p orm therefore, beca able of 'ad'ustment to suit th meanswhereby the length of stroke ofthe plunger requirements ofpthe Springs being tested;

stated before, the table '7 may be raisedand lowh? mventloP 1Slnustrapted the accompany ered to change therelation between the plungerdraifvlng t -f 16 and the scale platform 13. I have alsoshown 1 Fi u 1is a s d v w of a spring t n aa set screw at 28 whereby the collar 23maybe chine embodying my invention; fixed to the plunger 16 in any desiredposition so i Fig. 2 is an enlarged elevational view of the. that theplunger may be raised or lowered with" er hasbeenadjusted so as to leavethe proper respect to the platform when the set screw is 32 threading onthe shank 30 is arranged to jam' against the lower end of the plunger tomaintain the presser foot in its adjusted position. 1 Inoperation, theoperator in testing each spring, such that represented at 33, insertsthe same beneath the presser foot in the raised position of the plunger.Then, when the plunger is depressed he observes the dial to determinethe load exerted by the spring, it being understoodthat theplungclearance betweenthe presser foot 29 and the platform 13 with thespring in place therebetween and under compression. For example, if itis desired to know what load a spring three inches long will beunderwhen compressed toa length of, say, two inches, then the presserfoot should have a clearance of, exactly two inches with respect to theplatform with the spring compressed therebetween. t will be obvious thatthe plunger may be depressed as many as thirty times per minute andstill afford enough of a time interval for the operator to get a readingoff the dial without too much eyestrain. As stated before, the

- operation of the plunger by the crank and pitman rod insures enough ofa dwell of the plunger at the lower end of its stroke to allow theindicator hand 15 to come to a standstill at a certain point on thedial. With ordinary skill, an operator --experiences no difficulty inremoving one spring and substituting another to keep up with the speedof operation of the plunger so as to test thirty or more springs perminute, which is approximately twice the output produced with anordinary hand operated spring testing rig. Thus, a large number ofsprings of a certain length for a certain prescribed purpose maybetested for uniformity at a very low labor cost and such springs as proveto be too weak or too strong may be laid aside as unfit for theparticular purpose contemplated.

In Figs. 2 and 3 I have shown an adjustment whereby the length ofstrokeof the plunger- 16 may be varied to suit therequirements of differentjobs. It will be evident that by simply changing the throw of the crankpin 26 the length of stroke of the plunger is accordingly varied. Withthis end in view I-provide 'the crank pin 26 in theform of a bolt havinga T head 34 'adjustably mounted in a T slot 35 extending diametricallyacross the face of the disc-shaped crank element 27. A nut 36 thread ingon the shank near the head 34 is arranged,

when tightenedrtohold theipin 26 in any de-' sired position inthe slot35. The ball 37 received in the socket 38 in the lower end of thevpitman rod 25 provides a suitable universal joint connection allowingfor the rotation of the pit- ;man rod 25 relative-to the 'crank'pin 26as re-.

quired in operation. I a

It is believed the foregoing description conveys a clear understandingof my invention and of its various objects and advantages. Whilereference has been made particularly to the use of the machine for thetesting of coiledcompression springs it will be apparent that otherkinds of springs, or for that matter, other kinds of materials mightalso be susceptible of being tested. The claims have, therefore, beendrawn with a viewto covering all legitimate modifications andadaptations of the invention.

I claim:

1. A machine for measuring the compressive strength of coil springscomprising a frame, a vertically adjustable bracket on said frame, aforcemeasurement platform on said bracket'positioned to serve as a lowerabutment for a coil spring under test, a force indicating dial having apointer, means connecting said pointer to said platform'to indicate theforce exerted by said spring, a plunger above said platform reciprocabletoward and away from said platform, a presser foot adjustable 'on thelower end ofsaid plungedand serving as an upper abutment forsaid'spring, a pivotally supported lever having one end thereofreleasably secured to said plunger for driving said plunger and varyingthe clearance between said presser foot and said platform, an adjustablei pitman secured to the opposite end of said lever for oscillating-saidlever and reciprocating. said 'plunger through any of a plurality ofstrokes,

and means for continuously driving said pitman.

2. In a testing machine of the character described for measuring thecompressive strength of coil springs, thecombination of aforce-measurement platform, a plunger reciprocable toward andawayfrom-the' platform, apower operated 0 means for reciprocating saidplunger including' a motor and an adjustablepitman forconverting therotary motion of the motor into reciprocal motion of'variable stroke,means for obtaining 'a predetermined clearance between the plunger,

and the platform at the .end of ,each reciproca tion, for the purpose ofcompressingeach spring inserted therebetween'to a predetermined extent,dial means for visually indicating the force exerted on saidplatform'bythe compression of said springs, and means for adjustingrtheposi tion of the force-measurement platform with respect to theplunger.r

' CARL A. THELAVND'ER.

